<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style type="text/css">
    .container {}

    .container .cart {
      width: 300px;
      margin: auto;
    }

    .container .title {
      background-color: lightblue;
      height: 40px;
      line-height: 40px;
      text-align: center;
      /*color: #fff;*/
    }

    .container .total {
      background-color: #FFCE46;
      height: 50px;
      line-height: 50px;
      text-align: right;
    }

    .container .total button {
      margin: 0 10px;
      background-color: #DC4C40;
      height: 35px;
      width: 80px;
      border: 0;
    }

    .container .total span {
      color: red;
      font-weight: bold;
    }

    .container .item {
      height: 55px;
      line-height: 55px;
      position: relative;
      border-top: 1px solid #ADD8E6;
    }

    .container .item img {
      width: 45px;
      height: 45px;
      margin: 5px;
    }

    .container .item .name {
      position: absolute;
      width: 90px;
      top: 0;
      left: 55px;
      font-size: 16px;
    }

    .container .item .change {
      width: 100px;
      position: absolute;
      top: 0;
      right: 50px;
    }

    .container .item .change a {
      font-size: 20px;
      width: 30px;
      text-decoration: none;
      background-color: lightgray;
      vertical-align: middle;
    }

    .container .item .change .num {
      width: 40px;
      height: 25px;
    }

    .container .item .del {
      position: absolute;
      top: 0;
      right: 0px;
      width: 40px;
      text-align: center;
      font-size: 40px;
      cursor: pointer;
      color: red;
    }

    .container .item .del:hover {
      background-color: orange;
    }
  </style>
</head>

<body>
  <div id="app">
    <div class="container">
      <my-cart></my-cart>
    </div>
  </div>
  <script type="text/javascript" src="js/vue.js"></script>
  <script type="text/javascript">
    var CartTitle = {
      props: ['uname'],
      template: `
        <div class="title">{{uname}}商品</div>
      `
    }
    var CartList = {
      props: ['list'],
      template: `
        <div>
          <div class="item" v-for="item in list" :key="item.id">
            <img :src="item.img"/>
            <div class="name">{{item.name}}</div>
            <div class="change">
              <a href="" @click.prevent="sub(item.id)">－</a>
              <input type="text" class="num" :value="item.num" @blur="changeNum(item.id,$event)" />
              <a href="" @click.prevent="add(item.id)">＋</a>
            </div>
            <div class="del" @click="del(item.id)">×</div>
          </div>
        </div>
      `,
      methods: {
        del(id) {
          this.$emit('btn-del',id);
        },
        changeNum(id,event) {
          // console.log(id,event);
          //虽然有+-或直接修改3种事件改变数量，那么我们可以将这几种事件增加一个自定义属性type，来区分，这样就无须每个事件绑定一个事件了，且因为传递的参数有多个，我们可以用对象存储后传递
          this.$emit('change-num',{
            id:id,
            type:'change-num',
            num: event.target.value
          })
        },
        sub(id) {
            this.$emit('change-num',{
              id:id,
              type:'sub'
            })
        },
        add(id) {
            this.$emit('change-num',{
              id:id,
              type:'add'
            })
        }
      }
    }
    var CartTotal = {
      props: ['list'],
      template: `
        <div class="total">
          <span>总价：{{getSum}}</span>
          <button>结算</button>
        </div>
      `,
      computed: {
        getSum() {
          let total = 0;
          this.list.forEach(item => {
            total += item.price * item.num;
          })
          return total;
        }
      }
    }
    Vue.component('my-cart', {
      data() {
        return {
          uname: '张三',
          list: [{
            id: 1,
            name: 'TCL彩电',
            price: 1000,
            num: 1,
            img: 'img/a.jpg'
          }, {
            id: 2,
            name: '机顶盒',
            price: 1000,
            num: 1,
            img: 'img/b.jpg'
          }, {
            id: 3,
            name: '海尔冰箱',
            price: 1000,
            num: 1,
            img: 'img/c.jpg'
          }, {
            id: 4,
            name: '小米手机',
            price: 1000,
            num: 1,
            img: 'img/d.jpg'
          }, {
            id: 5,
            name: 'PPTV电视',
            price: 1000,
            num: 2,
            img: 'img/e.jpg'
          }]
        }
      },
      template: `
        <div class='cart'>
          <cart-title :uname="uname"></cart-title>
          <cart-list :list="list" @btn-del="dele" @change-num="changeNum"></cart-list>
          <cart-total :list="list"></cart-total>
        </div>
      `,
      components: {
        'cart-title': CartTitle,
        'cart-list': CartList,
        'cart-total': CartTotal
      },
      methods: {
        dele(id) {
          var index =  this.list.findIndex(item => {
            if(item.id == id) {
              return true;
            }
          })
          this.list.splice(index,1);
        },
        changeNum(ele) {
          // console.log(ele);
          if(ele.type == 'change-num') {
            this.list.some(item => {
              if(item.id == ele.id) {
                item.num = ele.num;
                return true;
              }
            })
          }else if(ele.type == 'add') {
            this.list.some(item => {
              if(item.id == ele.id) {
                item.num++;
                return true;
              }
            })
          }else if(ele.type == 'sub') {
            this.list.some(item => {
              if(item.id == ele.id) {
                item.num--;
                item.num = item.num < 0 ? 0 : item.num;
                return true;
              }
            })
          }
        }
      }
    });
    var vm = new Vue({
      el: '#app',
      data: {

      }
    });
  </script>
</body>

</html>